Product Overview

The Sta-Rite System 3 Modular Media Filter | S7M400 is a high-capacity cartridge-style pool filter designed for strong water clarity, long filter cycles, and simplified maintenance. With 400 square feet of filtration area and a maximum flow rate of 115 GPM, this filter is built for residential inground pools, spas, and water feature systems that need dependable filtration performance.

Unlike traditional sand or DE filters, the System 3 Modular Media design does not require backwashing. Instead, the internal modular cartridges are removed, rinsed, and reinstalled when cleaning is needed. This helps conserve water, simplify maintenance, and reduce the need for backwash plumbing.

Built with Sta-Rite’s durable Dura-Glas® glass-reinforced composite resin tank, balanced-flow hydraulics, and secure Posi-Lok™ clamp system, the S7M400 is a professional-grade filtration option for pool owners who want efficient, low-maintenance cartridge filtration.

Ideal For

• Residential inground swimming pools
• Inground spas and hot tubs
• Pool and spa combination systems
• Water feature circulation systems
• Pools up to approximately 55,000 gallons
• Customers wanting no-backwash filtration
• Equipment pad upgrades
• Replacing older cartridge filters
• High-capacity filtration applications
• Professional pool equipment installations

Key Features

• 400 sq. ft. filtration area — large media surface area helps capture dirt, debris, and fine particles.
• 115 GPM maximum flow rate — supports strong circulation for compatible pool systems.
• Modular media cartridge design — uses inner and outer cartridge elements for high-capacity filtration.
• No backwashing required — cartridges are cleaned by rinsing, helping reduce water waste.
• Dura-Glas® reinforced tank construction — durable glass-reinforced composite resin built for outdoor pool environments.
• Balanced-flow hydraulic design — helps distribute water evenly through the filter media for improved filtration performance.
• Integral manifold design — supports efficient water flow and cartridge performance.
• Posi-Lok™ clamp system — provides secure tank closure and service access.
• 2" tank ports — supports standard high-flow pool plumbing connections.
• Long cleaning cycles — large dirt-holding capacity helps extend time between filter cleanings.
• Professional-grade SM Series design — part of Sta-Rite’s System 3 Modular Media filter line.

Benefits

The Sta-Rite S7M400 System 3 filter is designed to deliver excellent water clarity with less routine maintenance than many smaller cartridge filters. Its large modular media design provides a high dirt-holding capacity, which helps extend filter cycles and reduce how often cartridges need to be cleaned.

Because the filter does not require backwashing, it can help conserve water and simplify equipment pad design. The durable Dura-Glas tank and secure Posi-Lok clamp system make it a strong choice for long-term residential pool filtration.

For pool owners looking for a high-capacity, no-backwash filter with strong hydraulic performance, the S7M400 is a reliable upgrade option.

Specifications

Included Components

• 1 × Sta-Rite System 3 S7M400 modular media filter tank assembly
• Inner modular cartridge element
• Outer modular cartridge element
• Posi-Lok clamp assembly
• Internal manifold components
• Manufacturer-supplied installation documentation

Plumbing unions, valves, additional fittings, replacement cartridges, O-rings, pressure gauge, air relief components, and installation materials may vary by supplier packaging. Confirm included components before installation.

Installation Notes

The Sta-Rite S7M400 should be installed by a qualified pool professional. Proper installation requires correct plumbing alignment, flow rate verification, equipment pad spacing, pressure testing, and startup inspection.

Before installation, confirm that the pool pump flow does not exceed the filter’s 115 GPM maximum flow rating and that the system is designed for compatible 2" plumbing. The filter should be installed on a level, stable equipment pad with enough clearance around the tank for cartridge removal and routine service.

Always turn off the pump and relieve system pressure before opening the filter tank. Never loosen or remove clamps while the filter is pressurized.

Customer-Facing Q&A

Q: What is the Sta-Rite S7M400?
A: It is a Sta-Rite System 3 SM Series modular media cartridge filter with 400 sq. ft. of filtration area and a maximum flow rate of 115 GPM.

Q: What is the SKU?
A: The SKU is S7M400.

Q: What is the UPC?
A: The UPC is 022315302242.

Q: Is this a cartridge, sand, or DE filter?
A: This is a modular media cartridge filter.

Q: Does this filter require backwashing?
A: No. The cartridges are removed and rinsed for cleaning, so routine backwashing is not required.

Q: What is the filtration area?
A: This filter has 400 sq. ft. of total filtration area.

Q: What is the maximum flow rate?
A: The maximum flow rate is 115 GPM.

Q: What size pool can this filter support?
A: It is commonly listed for pools up to approximately 55,000 gallons, depending on turnover requirements, pump sizing, plumbing design, and local code.

Q: What size plumbing ports does it have?
A: The S7M400 uses 2" tank ports.

Q: What cartridges does this filter use?
A: It uses a two-piece modular cartridge set: a large outer cartridge and a smaller inner cartridge for the S7M400 system.

Q: What is the tank made from?
A: The tank is made from Sta-Rite’s Dura-Glas glass-reinforced composite resin.

Q: Is this for above-ground or inground pools?
A: This model is designed for inground pool applications, as well as compatible inground spas, hot tubs, and water feature systems.

Q: Should this be professionally installed?
A: Yes. Professional installation is recommended to ensure proper plumbing, pressure testing, flow rate, and safe operation.